Suchergebnisse

In the work presented, the focus is on the influence of the EGR operation on the engine performance factors. Basic principles of the EGR operation are considered and experiment with electronically controlled engine is carried out on a Kongsberg marine simulator. The influence of the EGR on the efficiency, specific fuel consumption and CO2 emissions is evaluated. Recommendations for the performance adjustment of the supercharging system are stated.

The current restrictions on emissions from marine engines, particularly sulphur oxides (SOx ), nitrogen oxides (NOx ) and carbon dioxide (CO2 ), are compelling the shipping industry to a change of tendency. In the recent years, many primary and secondary reduction techniques have been proposed and employed in marine engines. Nevertheless, the increasingly restrictive legislation makes it very difficult to continue developing efficient eduction procedures at competitive prices. According to this, the paper presents the possibility to employ alternative fuels. A numerical model was developed to analyze the combustion process and emissions using oil fuel, natural gas and hydrogen. A commercial marine engine was studied, the Wärtsilä 6L 46. It was found, that hydrogen is the cleanest fuel regarding CO2 , hydrocarbons (HC) and carbon monoxide (CO). Nevertheless, it is very expensive for marine applications. Natural gas is cheaper and cleaner than fuel oil regarding CO2 and CO emissions. Still, natural gas emits more NOx and HC than oil fuel. SOx depends basically on the sulphur content of each particular fuel. ; SI

Small naval vessels are equipped with high- and medium-speed engines with low diagnostic compliance. Faults in fuel installations are the most common cause of failure or inability to perform operational scenarios adequately. Identification of injector damage is severe as small engines are not equipped with indicators and thermocouples to measure the overall exhaust gas temperature in the exhaust manifold. The paper presents a vibration method for assessing the technical condition of a fuel installation. The proposed method is non-invasive and allows the indication of a damaged injector within a relatively short time. The paper presents simulation results verified with stand-bed tests. The research aimed to show the sensitivity and uniqueness of vibration symptoms to changes in the technical condition of fuel injection pumps. The conducted experiment confirmed the possibility of using vibration tests in the professional diagnostics of the fuel installation. These results are essential for the use of marine engines that do not have indicator valves.